Iranian President Hasan Rouhani addresses the 68th United Nations General Assembly on Sept. 24, 2013, in New York. / Brendan McDermid, AP

by Oren Dorell, USA TODAY

by Oren Dorell, USA TODAY

Newly energized nuclear talks with Iran starting Thursday could be an Iranian scam to stave off a military attack, lift economic sanctions and play for time while putting the finishing touches on its nuclear program, or to cut a deal that will leave in place the infrastructure for building a bomb, analysts say.

Experience with rogue nations seeking nuclear capabilities, such as North Korea, shows that Iran could use negotiations to play for time. And the wrong kind of deal could leave the Islamic Republic with the ability to develop a nuclear weapon whenever its clerical leaders see fit, said Mark Dubowitz, executive director of the Foundation for Defense of Democracies.

If Iran retains domestic nuclear fuel production, a central component to the Iranian nuclear program, "there is a risk that Iran will at a time of its choosing break out or sneak out to a nuclear weapon," said Dubowitz, an expert on Iran sanctions and nuclear proliferation.

Others see it as an opportunity.

Barry Pavel, vice president of the Atlantic Council in Washington, said upcoming talks at the United Nations should be given a chance even though years of previous talks failed to dissuade Iran from progressing in its nuclear program.

"It's a very good opportunity that should be tested in great detail," Pavel said. "We don't have to trust them, we just have to come to a deal that is verifiable, where trust is not an issue."

Iran's foreign minister is urging step-by-step compromises between his country and world powers to advance negotiations over Tehran's nuclear ambitions. Mohammad Javad Zarif's remarks on Iran's state TV referred to "phased actions" after reviving stalled talks with a six-nation group - the five permanent members of the United Nations Security Council plus Germany.

U.S. Secretary of State John Kerry and other envoys are scheduled to meet with Zarif on Thursday in New York to discuss restarting the talks.

Israel, which has fought several wars with Iranian allies Syria and Hezbollah, the Iranian-backed Shiite militia in Lebanon, has warned that an Iranian nuclear weapon would be an existential threat, and Israel's defense forces have been training for long-range operations that analysts say are preparations for an attack on Iran's nuclear facilities.

Iran has said its right to enrich uranium is non-negotiable, while American policy on the issue is unclear.

President Obama told the U.N. General Assembly on Tuesday that the USA is determined to prevent Iran "from developing a nuclear weapon," and that "we respect the right of the Iranian people to access peaceful nuclear energy."

Obama then announced that he had instructed Kerry to engage directly with the Iranians.

Iranian President Hasan Rouhani told the General Assembly his country is ready to resolve issues over its nuclear program with "full transparency," and also described a peaceful nuclear program and enrichment as "two inseparable parts" of any political solution.

Rouhani said that "nuclear weapons and weapons of mass destruction have no place in Iran's defense doctrine."

Pavel said a deal should be tried even though Rouhani is not ultimately in charge of Iran's nuclear program â?? that power is in the hands of Supreme Leader Ayatollah Ali Khamenei â?? and even though Iran has shown that "it is a bad regime."

Iran has been a main supporter of Syrian dictator Bashar Assad who has killed about 120,000 Syrians in his ongoing civil war. It has plotted to assassinate a Saudi diplomat in Washington, D.C., and sponsored acts of terrorism against Americans and Jewish targets around the world. Its leaders in the past have questioned the existence of Israel, a major U.S. ally in the Middle East, while developing a nuclear program and long-range missiles capable of launching a warhead.

Still, a deal that includes low-level enrichment and monitoring to prevent it from going further may be workable, Pavel said.

"There may be a compromise regarding enrichment that can be verifiable," he said.

But Dubowitz said any enrichment capability is too big a risk because "no safeguards regime can stop a country dedicated to building nuclear weapons."

U.S. intelligence failed to keep tabs on the Iraqi nuclear program, which Israel destroyed in 1981, and which international inspectors discovered after the first Gulf War was being reconstituted. U.S. intelligence also missed the nuclear reactor Syria bought from North Korea, which Israel destroyed in 2007; and it failed to catch multiple violations of nuclear agreements with North Korea, Dubowitz said.

Of the world's 33 countries with nuclear power, nine have or are believed to have nuclear weapons. Only five nations other than Iran can produce nuclear fuel and are weapons-free: Argentina, Brazil, Germany, Japan and the Netherlands.

"If you think Iran looks more like those five, then there's no problem allowing it to enrich," Dubowitz said. "But if you're afraid Iran looks more like North Korea or Pakistan and more likely to become the 10th nuclear power then are you willing to take the risk?"

The question of permitting Iranian domestic nuclear fuel production should be theoretical until Iran "comes clean" on its past nuclear weaponization activities, as described by the United Nations nuclear watchdog inspectors, Dubowitz said.

Another risk of talks, Pavel said, is that as they proceed and Iran presents a conciliatory approach to the world, nations that have sided with the United States in imposing sanctions may leave the sanctions coalition, removing the incentive that has forced Iran to the negotiating table.

The world has a mixed track record of preventing nations from developing nuclear weapons.

South Africa dismantled its nuclear weapons under sanctions in 1989. Libya abandoned its nuclear weapons program in 2004, after the U.S. invasion of Iraq over weapons of mass destruction. Yet North Korea continued to develop its nuclear weapons while simultaneously negotiating to abandon them in years of talks similar to the ones with Iran, Pavel said.

North Korea signed two agreements limiting its nuclear activities during the presidencies of Bill Clinton and George W. Bush and now is considered a nuclear weapons state.

"That's definitely the strategy (Iran) is using up to this point, North Korean tactics," Pavel said. "And the North has about a dozen nuclear weapons up to this point."